Animated displacement of rigid body does not collide with other rigid bodies
many thanks for your help. 

I actually did it in an indirect way, a few days ago, by using arrays of passive/animated rigid bodies and connecting them to the animated plane by using Shrink Wrap. This created a moving floor (up-down motion), that interacted with the active/rigid icospheres, giving the result I wanted. Many thanks for your help and I will try the suggested methods to see if they work too.